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(No Model.) 2 Sheets-Sheet 1.

O. E. A. RATEAU. PROPELLER 0R BLOWER.

No. 500,080.. Patented June 20, 1893.

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, UNITED STATES PATENT OFFICE.

CAMILLE EDMOND AUGUSTE RATEAU, OF ST. ETIENNE, FRANCE.

PROPELLER OR BLOWER SPECIFICATION forming part of Letters Patent No.500,080, dated June 20, 1893.

. Application filed September 2, 1892, Serial No. 444,899. (No model.)

To all whom it may concern.-

Be it known that I, OAMILLE EDMOND AU- GUSTE RATEAU, of St. Etienne, inthe Department of the Loire, France, have invented new and usefulImprovements in Propellers orBlowers, which are fully set forth in thefollowing specification;

This invention has reference to the construction of screw-propellers orhelices for the propulsion of boats, or balloons,or for use asventilators and pumps to propel aeriform and liquid fluids. In the firstcase the helices have their opposition or resistance in the fluid (wateror air), and push the vessel. In the second case they bear upon astationary support, and propel the fluid. The helices now in use forthese purposes, are generally formed of blades, few in number (four,six, or sometimes eight) fixed upon a hub ,of greater or less diameter.Each blade or wing is usually a part of a right helicoid, '5. 6., itssection when out by a cylinder concentric with the axis is in everyportion a helix. The extremities of the wings are generally free.Sometimes they may have secured to them a cylindrical flange flaringinto a diverging cone. It is easy to conceive that helices thus madecannot have a great working; capacity, because they work by a successionof shocks or concussions.

If it isdesired to approach theoretical perfection it is necessary torealize the following conditions. (First) The wings must take the fluidwithout any shock at the outer edge. (Second) The wings must thenprogressively push the fluid, and .to this end it is necessary that itssection when out by a cylinder concentric with the axis should be an arcof a circle. (Third) The wings should be sufficiently close together toeffect a regular flow of fluid between them, and thus avoid swirls andeddies, which produce retardation. (Fourth) As the compound centrifugalforce is directed toward the axis, and is generally greater than theimpelling centrifugal force (force centrifugal dentrainement) it isnecessary that the channels formed by the wings or blades shouldconverge instead of diverge. (The terms compound centrifugal force, andimpelling centrifugal force are used in accordance with the well knowntheory of Ooriolisand are expressions of accelerations rather than offorces. By calculation it is found that the former is nearly twice asgreat as the latter.) In order to conform to these theoreticalconditions, which I have only outlined, I form my helices in thefollowing manner: The wings or blades are made of steel sheets, and arecut from right conoids or out of right or oblique cylinders. They arefixed upon a large hub, whose radius comprisesbetween one half and fourfifths of the exterior radius of the helix. They are from twentyfour tothirty-six in number, and their extremities may be free, or may beriveted to a flange. is a cone converging toward the issue, that is inthe direction which the fluid takes.

In the accompanying drawings, Figure I, represents in elevation, partlyin section a propeller for vessels embodying the invention. Fig. II is apartial end view of the same. Fig. III represents partly in elevationand partly in section, a helicoidal ventilator with annular diffuser.Fig. IV is a partial end view thereof. Fig. V is an elevation partly insection of a duplexhelicoidal ventilator and a volute diffuser; and Fig.VI is a section thereof transverse to the axis.

Hal 00 for propelling b0ats.'-This helix is formed of a hub E G upon theflange II of which are fixed the sheet-steel wings or blades a b c d(Fig. I). The extremities of these wings are riveted to the inner faceof a frustum of a cone formed of sheet iron, represented in section(Fig. I) by the line J. K. In front of the hub is an ogive O L M, whichis fastened to the boat and designed to displace without two greatresistance, the liquid streams, and to carry them to the working portionof the helix. This ogive carries, by means of the web D, the bearingthrough which passes the shaft A B of the helix. In therear of the huband attached to the flange H thereof, is another ogive O N, also ofsheet iron, the object being to avoid the seething or violent agitationof the water discharged behind the screw. The wing .or blade seenendwise at a b c d, and in profile at a b c d (Fig. I), and in face viewin Fig. II, at a b, &c., is part of a right conoid, engendered by astraight line resting at one end upon the axis A B and perpendicularthereto, and at the other upon a curve a b traced upon a The peripheralsurface of the helix,

cylinder P K, which passes through the extremity of the wing. This curveis an arc of a circle traced upon the cylinder. At its origin, it makeswith the plane of entrance K K of the helix an angle, of which thetangent is equal to the ratio between the speed 9 h of the boat, and theperipheral speed of the helix, From the entrance a to exit I) thecurvature is from five to ten degrees as the case may be.

Helicoidal oentzlat'ing fan with annular dtfiuser, (Figs. III andIV.)-+The ventilator is composed of three parts, the distributer C, theturbine A B, and the diffuserD E.

The distributer is analogous to those of parallel turbines of theFontaiue type, and is formed of twenty-four wings of sheet iron curvedin arcs of circles cf sustained between two walls of cast iron. Thesewings are fixed, and their object is to give the streams or currents ofair a direction inclined about forty-five degrees to the axis, asindicated by the trajectory m n. The current of air is then seized bythe turbine. This is composed of twenty-four blades or wings formed fromcylindrical iron sheets, a. b c d, supported on the flange of a hub A B.These wings will be seen endwise at a b, forming an angle of abouttwenty degrees with the plane of rotation. They seize the air emergingfrom the distributer,and bring it parallel with the axis, propelling itforward along the trajectory p--q. The passage without shock from oneend to the other of the edge a. b is effected by means of the edge f hof the wing of the distributer, said edge being cut obliquely withrespect to the generatrix, so that the trajectory of the air is the moredeflected as it approaches the axis. The outer edge a b of the wingsoiiblades is brought as close as possible to the casing F so as to leavea minimum space for escape of air. The said casing F is in the form of afrustum of a cone converging toward the exit of the fluid. At the exitof the turbine the current enters the annular difiuser E D, where thevelocity is diminished by giving rise to increase of pressure. Thisdiifuser is composed of two casings or shells, one conical and the othercylindrical, united by means of radial wings t" j l. The air trajectorym npqis shown in dotted lines. The turbine could be used without thedittuser, but-the working capacity would not be as great. A greaterpressure may be obtained by arranging several apparatus one behind theother on the same shaft with or without the interposition of the wingeddistributer.

When the ventilator is used as a blower the casing O is open to theatmosphere. When it is used as an aspirator the air is brought to thedistributer by a cylindrical tubing whose axis may coincide with that ofthe ventilator, but it would be better to arrange this delivery tubpperpendicular to the axis of the ventilator, so that it may be tangentto the periphery of the casing O. The current is then thrown obliquelyto the axis, and the partitions of the distributer may be planes. Theymay also be entirely omitted by forming the channel of admission into avolute around the annular orifice of the shell or casing.

The helicoidal ventilator with volute diffuser.Figs. V. and VI.represent in elevation and section a duplex ventilator symmetricallyarranged with two helicoidal turbines, and a dilfuser in the voluteform. Thereis no distributer in this case, or rather it is reduced to a'shell R contracting toward the turbine. The latter is formed by twentyfour wings a b c d made of sheet metal, in the manner already explainedand secured upon the flange I G of a hub of cast iron. At a Z) will beseen the section of awing in an arc of a circle to allow of the entranceof air without shock. The edge of the wing is cut obliquely withreference to the generatrix, as seen at a b. ,/The two turbines arecoupled by means ol a sheet iron cylinder G H. At the exit oftheturbines the air onters a volute E F of l rectangular section,inolosed by the casing E E F F And on the surface which, is seen insection in Fig. VI, it has the spiral form a f g 72. The trajectory ofthe airis shown by dotted lines on n p q. The shaft A has pulley P.

The two systems of ventilation herein described may also beused as pumpsto elevate liquids,in which case the shaft is usually placed in avertical position.

I claim as my invention- 1. A propelling screw or helix comprisingnumerous blades secured to a hub of relatively large diameter, the formof each blade being described by a straight line moved with its innerend in contact with the hub, so that both ends describe-arcs of circles,said line being at all times substantially perpendicular to the axis ofthe hub, substantially as described. i

2. A propelling screw or helix comprising numerous blades secured to ahubof relatively large radius, each blade being cut from a rightconoid,,or from a rightor oblique cylinder, so that a section of theblade when out by any cylinder concentric with the axis is a circularare, substantially as described.

3. A propelling screw or helix comprising blades set close together upona hubof relatively large diameter, said blades presenting in section anare of a circle when out at any point by a cylinder concentric withtheaxis, the peripheral surface of the screw being a portion of a coneconverging toward the exit of the fluid, substantially as described.

4. The combination with thepropelling helix or screw formed of numerousblades upon a hub of relatively large diameter, as specified, of adistributor having fixed guiding or defleeting partitions, whereby thefluid is delivered to the helix obliquely to the axis there of,substantially as set forth.

5. The combination with the helix or screw formed of numerous bladeseach curved in an arc of a circle, upon a hub of relatively largediameter, of a distributer having guiding or deflecting .partitions orblades, curved in a direction opposite to the curve of the blades of thehelix, and a diffuser, substantially as described.

6. The combination with the propelling helix or screw, formed ofnumerous blades set upon a hub of relatively large diameter, of adistributer and a volute diffuser, substantially as set forth.

7. The combination of a plurality of prov pelling screws or helices uponthe same shaft each screw or helix being composed of numerous blades setupon a hub of relatively large diameter and curved in profile or sectionin the arc of a circle, substantially as described.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

OAMILLE EDMOND AUGUSTE RATEAU.

Witnesses:

ANTHONY PoLLoK, R. M. HOOPER.

